Optimized user equipment capabilities signaling including recovery from database failure

ABSTRACT

Methods and apparatus, including computer program products, are provided for UE capability signaling. An apparatus is provided that is caused to at least: receive, from a user equipment capability management function, a message including a first restart counter value indicating a restart of the user equipment capability management function; inhibit, in response to receiving the first restart counter value, one or more old user equipment capability identifiers associated with a second restart counter value, the second restart counter value being associated to a pre-restart state of the user equipment capability management function; and send the first restart counter value indicating the restart of the user equipment capability management function. Related systems, methods, and articles of manufacture are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to International Application No.PCT/US2019/030262, filed May 1, 2019, the entire contents of which areincorporated herein by reference.

FIELD

The subject matter described herein relates to wireless.

BACKGROUND

In cellular systems, the user equipment (UE) may provide to the networkcapabilities information, such as the UE's capabilities including itscapabilities for the radio access network (RAN). The size of the UE'scapabilities information may over time become significant. In 3GPPhowever, it is pursuing a work item on optimization of the UE's radiocapabilities signaling in Rel-16 (see, e.g., 800025, FS_RACS, “Study onoptimizations on UE radio capability signaling,” and 800097,FS_RACS_RAN, “Study on optimizations on UE radio capabilitysignaling—NR/E-UTRA Aspects”).

SUMMARY

Methods and apparatus, including computer program products, are providedfor user equipment capabilities signaling.

In some example embodiment, there may be provided an apparatus includingat least one processor and at least one memory including computerprogram code, the at least one memory and the computer program codeconfigured to, with the at least one processor, cause the apparatus toat least: receive, from a user equipment capability management function,a message including a first restart counter value indicating a restartof the user equipment capability management function; inhibit, inresponse to receiving the first restart counter value, one or more olduser equipment capability identifiers associated with a second restartcounter value, the second restart counter value being associated to apre-restart state of the user equipment capability management function;and send the first restart counter value indicating the restart of theuser equipment capability management function.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. The first restart counter value may be stored.When the apparatus receives a registration request including a userequipment capability identifier associated with the second restartcounter value and/or when inspecting for one or more user equipmentcapability identifiers being stored for registered user equipment, theapparatus may compare the second restart counter value to the firstrestart counter value to determine whether the second restart countervalue matches the first restart counter value. A message may be sent tothe radio access network to trigger retrieval of a user equipmentcapability information for a user equipment. The message may be sent,when the apparatus does not include in its cache a user equipmentcapability identifier associated to the second restart counter value. Anew user equipment capability identifier associated to the userequipment capability information including at least one radio capabilitymay be assigned to the user equipment, wherein the new user equipmentcapability identifier may be associated to the first restart countervalue. The assigned, new user equipment capability identifier may besent to the user equipment in a registration accept message, aconfiguration update message, a globally unique temporary identifierreallocation command message, and/or a non-access-stratum signalingmessage. A new user equipment capability identifier and/or the firstrestart counter value may be sent to a radio access network to enablethe radio access network to inhibit the use of the one or more old userequipment capability identifiers associated to the second restartcounter value. The user equipment capability identifier associated withthe first restart counter value and/or the first restart counter may bestored. The new user equipment capability identifier and/or the firstrestart counter value may be sent to a radio access network via an N2interface or an S1 interface message. Context information including theold user equipment radio capability identifier associated to the secondrestart counter value may be sent toward one or more user equipment. Thefirst restart counter value indicating the restart of the user equipmentcapability management function may be sent towards the radio accessnetwork. The apparatus may be comprised in or comprise a core networknode, an access and mobility management function, and/or a mobilitymanagement entity.

In some example embodiment, there may be provided an apparatus includingat least one processor and at least one memory including computerprogram code, the at least one memory and the computer program codeconfigured to, with the at least one processor, cause the apparatus toat least: receive a first user equipment capability identifierassociated with a first restart counter value indicating a restart ofthe user equipment capability management function; associate the firstuser equipment capability identifier with at least one user equipmentcapability; and store the first restart counter value and/or the firstuser equipment capability identifier associated to the at least one userequipment capability.

In some variations, one or more of the features disclosed hereinincluding the following features can optionally be included in anyfeasible combination. A registration request including the first userequipment capability identifier associated to the first restart countervalue may be sent to a core network via a radio access network. Thefirst restart counter value may indicate a more recent restart of theuser equipment capability management function when compared to a secondrestart counter value associated to a second user equipment capabilityidentifier for the apparatus. In response to the received first userequipment capability identifier, use of the second user equipmentcapability identifier may be inhibited. The inhibition of the seconduser equipment capability identifier may include deleting the seconduser equipment capability identifier. One or more user equipmentcapability identifiers associated to the second restart counter valuemay be cached after receipt of the first user equipment capabilityidentifier associated to the first restart counter value, and the cachemay include the corresponding user equipment capability information. Thefirst user equipment capability identifier associated to the firstrestart counter value may be received via a registration accept message,a configuration update message, a globally unique temporary identifierreallocation command message, and/or a non-access-stratum signalingmessage. The first user equipment capability identifier may be sent to aradio access network. The apparatus may be comprised in or comprise auser equipment.

The above-noted aspects and features may be implemented in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. The details of one or more variations of the subjectmatter described herein are set forth in the accompanying drawings andthe description below. Features and advantages of the subject matterdescribed herein will be apparent from the description and drawings, andfrom the claims.

DESCRIPTION OF DRAWINGS

In the drawings,

FIG. 1A depicts an example of a portion of a 5G system, in accordancewith some example embodiments;

FIG. 1B depicts an example of a portion of an Evolved Packet System, inaccordance with some example embodiments;

FIG. 2 depicts an example of a process flow for handling UCMF failuresand recovery, in accordance with some example embodiments;

FIG. 3 depicts an example of a process flow for handling a restartcounter value from the perspective of a network node, in accordance withsome example embodiments;

FIG. 4 depicts another example of a process flow for handling a restartcounter value from the perspective of a user equipment, in accordancewith some example embodiments;

FIG. 5 depicts an example of a network node, in accordance with someexample embodiments; and

FIG. 6 depicts an example of an apparatus, in accordance with someexample embodiments.

Like labels are used to refer to same or similar items in the drawings.

DETAILED DESCRIPTION

As noted, the user equipment (UE) may provide to the network UEcapabilities information, which may cause inefficiencies including wasteof storage resources, waste of spectrum, and the like as the size of theUE capabilities information increases. The 3GPP is proposing a solutionthat provides a centralized node, such as a UE Capabilities ManagementFunction (UCMF), to allocate a UE radio capability ID (also referred toas a UE capability ID). The UE radio capability ID represents the UE'scapabilities including the UE's radio capabilities with respect to theRAN. This UE radio capability ID may be provided by the network and/orUCMF to the UE, which stores the UE radio capability ID for the UE. Themapping of the UE radio capability ID to the associated UE'scapabilities information may also be cached in the network, such as at acore network node, radio access node, and/or the like. Later, the UEradio capability ID may be sent by the UE to the network in one or moremessages. In the 5G system for example, the UE radio capability ID maythen be sent by the UE to the network in one or more registrationmessages, while in EPS (Evolved Packet System), the UE radio capabilityID may then be sent by the UE to the network in one or more attachmessages (and/or tracking area update messages). In either case, thenetwork is aware (based on the UE radio capability ID) of the UE'scapabilities information including the UE's radio capabilities (e.g.,radio access technologies supported, radio frequency parameters,supported bands, etc.), without the network triggering a UE capabilitiesinformation enquiry process to obtain the UE's full set of radiocapabilities (thus saving signaling over the radio).

However, the use of the centralized node, such as the UCMF, may giverise to a problem with respect to failure, such as a hardware failure,software failure, data loss or corruption, and/or other issue requiringa restart or other type of recovery. For example, if the UCMF fails andthere is a corresponding data loss of some if not all of the UEcapabilities information, such as the mappings from each of the UE radiocapability IDs to the corresponding UE capabilities information (whichinclude the UE's radio capabilities), the failure may cause a problem ina public land mobile network (PLMN) because there is no possibility forthe PLMN to recover from the failure since the UEs' may have stale UEradio capability IDs while the RAN and core network may be caching staleUE radio capability IDs and the mapped UE capabilities information aswell.

Upon the UCMF's recovery from the failure, a solution to the notedproblem is to indicate (e.g., signal, send, tell, etc.) the UCMF'srecovery to the access and mobility management functions (AMFs) in the5G system or to the mobility management entities (MMEs) in EPS. And,this solution may also indicate to a UE to inhibit use of (e.g., erase,delete, flush, ignore, clean up, flag or indicate not to use, flag orindicate that the ID is stale, etc.) the UE radio capability ID storedat the UE which may no longer suitable for use with the network afterthe failure since the ID is stale. The use of the stale UE radiocapability ID may create a problem with respect to the PLMN not knowingwhether the UE's stored UE radio capability ID has been assigned beforea UCMF failure or after the UCMF's recovery. In short, after the UCMFfailure and restart, the PLMN does not know whether the UE radiocapability ID provided by the UE is pre-failure (and thus stale and/orno longer active or valid) or post-recovery (and thus stale and/oractive or valid). Hence, this approach has a drawback that the UE (whichhad received a UE radio capability ID before the failure) will need tobe told to inhibit use of its “stale” UE radio capability ID and thatthe network cannot determine whether or not the UE is using a “stale” UEradio capability ID. As such, there is a need to determine at which timethe UE capability ID was assigned (e.g., pre-UCMF recovery or post UCMFrecovery).

In some example embodiments, the UE radio capability ID may beassociated an indicator to indicate that the UCMF has been restarted.This indicator may take the form of a counter (hereinafter “restartcounter value”) of the UCMF in the PLMN. For example, a field of the UEradio capability ID may include the restart counter value. This restartcounter value may represent whether the current UE radio capability IDis stale (e.g., associated with a pre-failure state of the UCMF and thusnot associated with the latest value of the restart counter) or a new UEradio capability ID (e.g., associated with a post-recovery state of theUCMF and/or the latest value of the restart counter). Rather thaninclude the restart counter value as a field in the UE radio capabilityID, the restart counter value may be sent separate from the UE radiocapability ID. In some example embodiments, the restart counter valuemay be sent and stored along with the UE radio capability ID.

When the UCMF recovers after a failure, the UCMF may indicate to thecore network nodes a value for a restart counter, in accordance withsome example embodiments. This value may be another restart countervalue (e.g., a “new restart counter value”) to indicate that the UCMF'srestart counter value has changed, such as after the recovery from thefailure. In some example embodiments, the UCMF may indicate this newrestart counter value to one or more core network nodes proactively(e.g., without an explicit request from one or more core network nodes)or when requested or contacted by the one or more core network nodes.For example, the UCMF may include the restart counter value in responseto a core network node message, such as a request message and/or thelike. In some example embodiments, one or more core network nodes mayindicate the new restart counter values to one or more RAN nodes towhich the core network nodes are in contact with. The core network nodes(which receive a new restart counter) may provide the new restartcounter to the RAN proactively (via a message) or in the responsemessages to requests from the RAN nodes.

In some example embodiments, the use of some, if not all, of the storedUE radio capability ID (s) and the corresponding old mapping(s) (whichare associated with the old, pre-UCMF failure and/or recover) may beinhibited at the UE, radio access network, core network nodes, and othernodes. In the network, the RAN and the core network may keep the “stale”UE radio capability IDs cached for the handling of any existingregistered UEs (which may be using the stale UE radio capability IDSuntil the UE radio capability IDs are aged out of the cache according toa caching policy).

When the network such as the core network nodes and/or the like receive,from a UE, the UE radio capability ID, the network may compare theUE-provided restart counter value (which is included in the UE radiocapability ID or provided together with the UE radio capability ID) tothe latest UCMF-provided restart counter value. The UE radio capabilityID including the restart counter value may be received in a 5G systemregistration message or an attach (or tracking area update) message in4G/LTE/EPS. If there is a mismatch between the UE-provided restartcounter value and the latest UCMF-provided restart counter value, the UEradio capability ID received from the UE may not be used (e.g.,inhibited, etc.) by the network other than perhaps retrieve from itscache any available mapping of this UE radio capability ID (which isreceived from the UE) to the UE capabilities information. The mismatchsignals to the network node that the UE is using a stale UE radiocapability ID.

If the mismatch of the restart counter value is detected and/or the corenetwork does not store the old, stale restart counter values of the UEradio capability IDs provided by the UEs in its cache of UE radiocapability ID to UE capabilities information mappings, the network mayobtain the UE capabilities information for that UE. To that end, thenetwork may then request, receive, and/or retrieve the UE's capabilitiesinformation from the UE (e.g., via a UE capabilities informationenquiry). However, if the core network caches old, stale UE radiocapability IDs provided by the UE, the core network may use the newradio capability ID mapped to the these cached values of the UEcapabilities information (which correspond to the old, stale UE radiocapability ID received from the UE). In either the enquiry or cachecase, once the core network has the current set of UE capabilitiesinformation for the UE, the core network may request the UCMF to assigna new UE radio capability ID for the set of UE capabilities information.The “new” here indicates that the UE radio capability ID is after arestart of the UCMF and/or more recent in time than the old, stale UEcapability assigned by the UCMF before the failure and/or recovery.

The network may map and cache the UCMF's new UE radio capability IDassociated with (e.g., include, mapped to, etc.) the new restart countervalue to the UE capabilities information for the UE. The network maythen indicate to the UE the new UE radio capability ID (which isassociated with the new restart counter value) in the registrationaccept message in the 5G system or, as applicable, in an attach acceptor tracking area update accept message in the EPS. Alternately, the newUE radio capability ID (which is associated to the new restart countervalue) may be communicated to the UE in a UE configuration updatemessage in the 5G system, a globally unique temporary identifier (GUTI)reallocation command message in the EPS, and/or other types ofnon-access-stratum signaling message initiated from the core network andreceived by the UE in the 5G system and/or EPS. The UE may store theUCMF assigned restart counter value alongside the UE radio capability ID(in the case the restart counter value is not part of the UE radiocapability ID itself) as part of the set of UE radio capability IDs forthe PLMN. If the UE has other UE radio capability IDs for another set ofUE capabilities that the UE had signaled previously and the other UEradio capability IDs are associated to older UCMF restart countervalues, the UE may, based on local caching policy that takes intoaccount these are stale values, keep storing the UE Radio capability IDsassociated with older UCMF restart counter values related to otherpotential UE radio configuration the UE may signal in the future. An aimof the operator may include minimization of the times the UEcapabilities information are retrieved from the UE over the airinterface, so if these UE radio capability IDs related to other radioconfigurations are retained in the UE, these may be signaled in thefuture with the expectation the network may also store these IDs and beable to interpret them. However, in the UE and the network, the stale UEradio capability IDs (e.g., those that are associated to the old UCFMrestart counters) may be removed from cache/storage with priority versusthose that are associated to the current UCMF restart counter. Byrepeating this process that occurs every time a UE indicates UE radiocapability ID with a UCMF restart counter that is not current, or by theAMF/MME updating the UEs which have in their UE context in the AMF/MMEUE radio capability IDs that are stale even before these UEs contact theAMF and MME by registration/mobility management or othernon-access-stratum signaling messages, the UCMF's database of UE radiocapability IDs (which are each associated to associated UE capabilitiesinformation) may be re-populated for the UEs over time. And, this mayenable healing after the failure and recovery of the UCMF.

Before providing additional description regarding the UCMF's restartcounter value in accordance with some example embodiments, an example ofa portion of a 5G wireless network 100 is described with respect to FIG.1A. FIG. 1A depicts an example of network 100, in accordance with someexample embodiments. The network 100 may comprise 5G technology, as wellas other types of radio technology as well.

The network 100 may include one or more user equipment (UE), such as UE150A configured to wirelessly couple to at least one radio accessnetwork, such as 5G radio access network (RAN) 152 served by a wirelessaccess point, such as a 5G base station, an LTE base station (eNB), awireless local area network access point, a home base station, and/orother type of wireless access point. When visiting a network, the UE mayaccess the network's radio access network.

The network 100 may include a core network, which may include an accessand mobility management function (AMF) 154, a session managementfunction (SMF) 156, a user plane function (UPF) 158, a network exposurefunction (NEF) 166, an application function (AF) 182, and the like. Inthe example of FIG. 1A, devices 152-164 may be associated with avisiting public land mobile network (VPLMN) 166. The UPF may interfacewith a data network (DN) 196. The AMF 178 may interface with a user datamanagement function (UDM) in a home public land mobile network (HPLMN)170.

In the example of FIG. 1A, the network includes UCMF 199 including acounter 198 configured to provide the restart counter values, inaccordance with some example embodiments. The UCMF may be a core networknode, and the UCMF may interface to an AMF 154, the NEF 166, the AF 172,and/or other nodes as well.

FIG. 1A also depicts service interfaces, such as N1, N2, N6, etc. Thearchitecture, nodes (including AMF, SMF, as well as other devicesdepicted at FIG. 1A), and the service interfaces may be defined inaccordance with a standard, such as 3GPP TS 23.501, although otherstandards as well as proprietary interfaces may be used.

Some of the nodes of the network 100 may be implemented as dedicated,physical devices, while other elements may be virtualized. For example,a core network node such as the AMF, SMF, etc., may be hosted on adedicated machine, or it may be hosted on a virtual machine (which isexecuted on, for example, a computer or other type of physical dataprocessor) and instantiated dynamically with other virtualized corenetwork nodes functions. Moreover, although FIG. 1A depicts a certainquantity of nodes (e.g., a single RAN, AMF, etc.), other quantities ofeach of the nodes may be implemented as well. And although FIG. 1Adepicts a single visiting network and a single home network, otherquantities of visiting and/or home networks may be included as well.

FIG. 1B depicts an example of an EPS network 199 implementation, inaccordance with some example embodiments. FIG. 1B depicts the UCMF 199,which interfaces to a services capabilities exposure function (SCEF)188, an application function (AS) 172, and a mobility management entity(MME) 176. The network 199 also includes a UE 150A, an Evolved UMTSTerrestrial Radio Access Network (E-UTRAN) 174, a serving gateway (S-GW)180, a packet gateway (PGW) 178, and a home subscriber server (HSS) 182.

FIG. 2 depicts an example of a process 200, for use with the UCMF'srestart counter value, in accordance with some example embodiments.

At 210, the UCMF 199 may reset the UCMF's restart counter 198, whichgenerates a new restart counter value to indicate that the UCMF hasrecovered after a failure, in accordance with some example embodiments.The failure and recovery may be a total failure or a partial failurerelated to hardware, software, data loss, or some other reason causing aneed for a restart of the UCMF (e.g., an interrupt in the operation ofthe UCMF or a corruption of the UE radio capability IDs or mappedinformation). In the FIG. 2 example, the prior, old, stale countervalue, “x,” is incremented by 1 (“+1”) to indicate the new restartcounter value. Thus, a network node or UE may be able to determine thata UE radio capability ID including the prior restart counter value of“x” represents a “stale” UE radio capability ID that should not be used.In some example embodiments, the restart counter values are stored in apersistent manner in UCMF persistent storage to enable, upon recoveryafter failure, to increment the value of the restart counter value.

At 220, the UCMF 199 may notify another node, such as the AMF 154, ofthe new restart counter value, in accordance with some exampleembodiments. In response to the resetting of the counter at 210, theUCMF may notify the AMF of the new restart counter value by sending amessage. It can be appreciated based on this disclosure that any AMF(which may receive a restart counter from the UCMF in a proactive manneras indicated in FIG. 2) may have entered in contact with the UCMF atleast once and may obtained at that time a first value of the UCMFrestart counter for the UCMF and may have also subscribed to thesenotification from the UCMF (or this can be configured in the UCMF to bean automatic subscription any time the AMF has first contacted theUCMF). Alternatively or additionally, the new value of the restartcounter may be provided in a response message to a request from the UCMF(e.g., a request to assign a new UE radio capability ID for a UE or arequest to resolve a UE radio capability ID that a UE has provided in aregistration request message to the AMF.

At 230, the network node, such as the AMF 154, may inhibit the use ofone or more old, stale UE radio capability ID (s) and may store the newrestart counter value received at 220, in accordance with some exampleembodiments. The AMF may receive the new restart counter value anddetermine (e.g., based on a comparison to what was stored before thefailure and recovery of the UCMF) that the UCMF has reset the counter198 (e.g., due to a failure and recovery). As such, the AMF may inhibitthe use of (e.g., erase, delete, flush, ignore, clean up, flag orindicate not to use, flag or indicate that the ID is stale, etc.) someif not all of the old UE radio capability IDs associated with the old,stale restart counter values of the UCMF (and/or any associated mappedUE capability information). For example, the AMF may delete these old UEradio capability IDs or, alternatively, cache these old UE radiocapability IDs along with the mapped UE capabilities information with anindication that they are stale. Caching may allow the UE capabilitiesinformation to be re-assigned to the new UE radio capability ID whichmay reduce the need to request, via a UE capability enquiry message,from the UE their UE full set of capabilities information. In the FIG. 2example, the new restart counter value is x+1 while the stored restartcounter is x, so there is no match and the AMF may then delete or cacheas stale any UE radio capability IDs included or associated with theolder, stored restart counter is x. The AMF may, as noted, store the newrestart counter value received at 220.

At 240, the network node such as the AMF 154 may send to the RAN 152 thenew restart counter value, in accordance with some example embodiments.For example, the AMF may send, as part of a AMF configuration updatemessage, the UCMF's new restart counter value (which in this example is“x+1”) to the RAN in order to update the RAN with the UCMF's new restartcounter value.

At 250, the RAN 152 may inhibit the use of one or more old, stale UEradio capability ID (s) and may store the new restart counter valuereceived at 240, in accordance with some example embodiments. The RAN152 may, as in the case of the AMF at 230, may cache these old UE radiocapability IDs along with the mapped UE capabilities information with anindication that they are stale. In this way, the old UE radio capabilityIDs may be retrieved from cache if needed in the RAN for UEs that areregistered, connected, and continue to use the old values in their RANcontext. Returning to the previous example in which the new restartcounter value is x+1 and the stored restart counter is x, the RAN maydelete one or more UE radio capability IDs including or associated withthe restart counter value <x+1, or keep them cached as stale values inthe event these are still needed in the RAN for UEs that are stillregistered and connected and keep using the old values in their RANcontext. The RAN may, as noted, store the new restart counter value x+1received at 220.

At 260, the UE 150A may send to the network a message including the UEradio capability ID that further includes a restart counter value, inaccordance with some example embodiments. For example, the UE 150A maysend to the AMF 154 a registration request. The registration request mayinclude the UE radio capability ID including a restart counter value,which in the example of FIG. 2 is x. In response, the AMF may determine(e.g., based on a comparison to what was stored before the failure andrecovery of the UCMF) that the UE has a stale UE radio capability ID asthe new restart counter in this example is x+1. When this is the caseand/or the AMF has no longer the stale UE radio capability ID cached,the AMF may send a message to the RAN to retrieve the UE's capabilitiesinformation.

At 270, the AMF 154 may send a message, such as an initial context setup request message to the RAN 152 to trigger the RAN to enquire aboutthe UE's capabilities information, in accordance with some exampleembodiments. For example, an initial context step up request may includean indication, such as no UE radio capability ID and/or no capabilities.When received at the RAN, the indication may trigger the RAN to triggera UE capabilities enquire process to obtained information about the UEcapabilities.

At 280, the UE capabilities enquiry takes place, in accordance with someexample embodiments. For example, the RAN 152 may send a UE capabilityenquiry message to the UE 150A. This message represents a networkrequest to the UE to provide the UE's capabilities information and, inparticular, the UE's network including RAN capabilities information. Inresponse to the UE capability enquiry message, the UE may respond to theRAN with a UE capability information.

At 290, the RAN 152 may provide, via the N2 interface, to the AMF 154the UE capability information including the UE's radio capability, inaccordance with some example embodiments.

At 299, the UE may be assigned a new UE radio capability ID, inaccordance with some example embodiments. The assigned new UE radiocapability ID may be mapped to the UE's capabilities informationsignaled at 290 or the UE capabilities obtained from cache (e.g., UEcapabilities information that is still valid but mapped to an old, staleUE radio capability ID). Now that the AMF has the current UE capabilityinformation, the AMF may request the UCMF to provide a UE radiocapability ID for the UE's capability information, such as the radiocapabilities of the UE. When the UCMF returns this value to the AMF, theAMF provides this new UE radio capabilities ID value to the UE(associated with the new UCMF restart counter which is, in this example,“x+1”) in a registration accept message. Alternately, the UE radiocapability ID (including or alongside the new UCMF restart countervalue) may be communicated to the UE in a UE configuration updatemessage in the 5G system or other type of non-access-stratum signalingmessage initiated from the core network and received by the UE in the5GS. Also, the AMF may provide this new value of the UE radio capabilityID (including or alongside the new UCMF restart counter value which is,in this example, “x+1”) to the RAN in a UE context update or initialcontext setup request context message as specified in 3GPP TS 23.501 and3GPP TS 38.413. When the UE receives a UE radio capability ID (which maybe associated with the new UCMF restart counter), the UE may retain(which may be subject to caching policy that may take into account theseare stale IDs) the other UE radio capability IDs that it stores for thePLMN for other radio configurations with older restart counter values soUE can still indicate these to the network when it changes radioconfiguration in case the network also cached the stale values (an aimhere may be to minimize the need for triggering the UE radio capabilityenquiry 280).

FIG. 3 depicts an example of a process 300 for handling a UCMF's restartcounter value, in accordance with some example embodiments.

At 302, a network node, such as AMF 154, may receive from a UCMF 199 amessage including a restart counter value, in accordance with someexample embodiments. The network node, such as the AMF, may determinethat when it receives the UCMF message including the restart countervalue, the UCMF has recovered from a failure or some other type of eventrequiring deletion of older UE radio capability IDs or marking them asstale in its cache.

In response to receiving the restart counter value, the network node,such as the AMF 154, may inhibit, at 304, the use of one or more old UEradio capability ID (s) (e.g., delete, mark them as stale, and/or keepthem in the cache), in accordance with some example embodiments.Moreover, the network node may store, at 306, the new restart countervalue received as noted above at 230, in accordance with some exampleembodiments.

The network node, such as the AMF 154, may send, at 308, the UCMF's newrestart counter value to other nodes, such as the RAN 152, in accordancewith some example embodiments. For example, the AMF may send, as part ofan AMF configuration update, the UCMF's new restart counter value to theRAN (or other nodes including the UE).

At 310, the network node, such as the AMF 154, may receive aregistration request including a restart counter value, in accordancewith some example embodiments. For example, the AMF may receive UE radiocapability ID including the restart counter value having a value of x.As such, the AMF may determine (e.g., based on a mismatch or comparisonto what was stored before the failure and recovery of the UCMF) that theUE has a stale UE radio capability ID as the new restart counter in thisexample is x+1. When it is determined that the UE capability is stalebased on the restart counter value as noted above, this may trigger theAMF to send, at 312, to the RAN 152 a message to retrieve the UE'scapabilities information. However if the AMF stores in the cache thestale UE radio capability ID value (which is associated with thereceived, stale restart counter value) along with the UE radiocapability information mapped to that ID, the AMF may not need totrigger retrieval of the radio capabilities from the UE, but instead theAMF may use the cached UE capabilities information (e.g., the radiocapabilities).

At 314, the network node, such as the AMF 154, if it had triggered UEcapabilities retrieval at 312, may receive, via the N2 interface, the UEcapability information including the UE's radio capability. The networknode, such as the AMF 154, may assign, at 316, to the UE a new UE radiocapability ID as noted above at 299. The assignment may includerequesting the UCMF to provide the UE radio capability ID correspondingto the current set of UE capabilities (e.g., radio capabilities of theUE) and to send to the UE in a registration accept message for example.Alternatively, the UE radio capability ID including or associated withthe new UCMF restart counter value may be communicated in a UEconfiguration update message in the 5G system or other type ofnon-access-stratum signaling message that is initiated from the corenetwork and received by the UE in the 5G system). If the UE receives aUE radio capability ID with a new restart counter, the UE may inhibituse of the corresponding UE radio capability ID with the old UCMFrestart counter. But the UE may still retain any other UE radiocapability IDs for other UE radio configurations with old restartcounters in the event that these needs signaling when the UE changesradio configuration and the network caches these old values (thusavoiding the need to trigger UE capabilities retrieval from the AMF),with the understanding the UE caching policies can take into accountthese are stale IDs.

FIG. 4 depicts another example of a process 400 for handling a UCMF'srestart counter value, in accordance with some example embodiments.

At 405, the UE 150A may send towards the AMF 154 a registration requestincluding a restart counter value, in accordance with some exampleembodiments.

When the restart counter value the UE sent is stale and the AMF does notcache the UE radio capability ID value the UE sent including orassociated with this stale UCMF restart counter the UE may receive, at410, from the network a request to provide UE capabilities information,in accordance with some example embodiments. For example, the UE 150Amay receive a UE capability enquiry message from the RAN 152, whichtriggers the UE to respond by providing, at 412, to the network (e.g.,RAN, AMF, etc.) the UE's current UE capability information includingradio capabilities.

And when the restart counter value is stale, the UE may receive in aregistration accept message from the AMF (or in a UE configurationupdate message in the 5G system or other non-access-stratum signalingmessage that is initiated from the core network and received by the UEin the 5G system), at 415, another UE radio capability ID mapped to theUE capabilities information provided at 412. For example, the other UEradio capability ID may comprise a new UE radio capability ID includingor associated with the new restart counter generated after the recoveryas noted above at 210. At 420, the UE may store the new UE radiocapability ID (which includes the new restart counter) mapped to the UEcapabilities information and erase the corresponding old UE radiocapability ID value. The UE may, as noted, retain other UE radiocapability IDs for other UE radio configurations with old restartcounter values.

In some example embodiments, when the AMF detects in the UE context(which the AMF stores for a UE that is already registered)a stale UEradio capability ID value, the AMF may proactively update the UE with anew UE radio capability ID without waiting for the next UE registration,using a UE configuration update message in the 5G system (5GS) or in aGUTI reallocation command message in the EPS, and/or some other type ofnon-access-stratum signaling message initiated from the core network andreceived by the UE in the 5GS and/or EPS.

FIG. 5 depicts a block diagram of a network node 500, in accordance withsome example embodiments. The network node 500 may be configured toprovide one or more network side functions, such as a base station(e.g., RAN 152), AMF 154, UCMF 199, and/or other network nodes.

The network node 500 may include a network interface 502, a processor520, and a memory 504, in accordance with some example embodiments. Thenetwork interface 502 may include wired and/or wireless transceivers toenable access other nodes including base stations, devices 152-180, theInternet, and/or other nodes. The memory 504 may comprise volatileand/or non-volatile memory including program code, which when executedby at least one processor 520 provides, among other things, theprocesses disclosed herein with respect to the network node (see, e.g.,process 200, 300, and/or the like). For example, the network node may beconfigured to at least receive, from a user equipment capabilitymanagement function, a message including a first restart counter valueindicating a restart of the user equipment capability managementfunction. The network node may also inhibit, in response to receivingthe first restart counter value, one or more old user equipmentcapability identifiers associated with a second restart counter value,the second restart counter value being associated to a pre-restart stateof the user equipment capability management function. The network nodemay also send the first restart counter value indicating the restart ofthe user equipment capability management function. The network node mayalso be configured to provide one or more of the following. When thenetwork node receives a registration request including a user equipmentcapability identifier associated with the second restart counter valueand/or when inspecting for one or more user equipment capabilityidentifiers being stored for registered user equipment, the network nodemay compare the second restart counter value to the first restartcounter value to determine whether the second restart counter valuematches the first restart counter value. A message may be sent to theradio access network to trigger retrieval of a user equipment capabilityinformation for a user equipment. The message may be sent, when thenetwork node does not include in its cache a user equipment capabilityidentifier associated to the second restart counter value. A new userequipment capability identifier associated to the user equipmentcapability information including at least one radio capability may beassigned to the user equipment, wherein the new user equipmentcapability identifier may be associated to the first restart countervalue. The assigned, new user equipment capability identifier may besent to the user equipment in a registration accept message, aconfiguration update message, a globally unique temporary identifierreallocation command message, and/or a non-access-stratum signalingmessage. A new user equipment capability identifier and/or the firstrestart counter value may be sent to a radio access network to enablethe radio access network to inhibit the use of the one or more old userequipment capability identifiers associated to the second restartcounter value. The user equipment capability identifier associated withthe first restart counter value and/or the first restart counter may bestored. The new user equipment capability identifier and/or the firstrestart counter value may be sent to a radio access network via an N2interface or an S1 interface message. Context information including theold user equipment radio capability identifier associated to the secondrestart counter value may be sent toward one or more user equipment. Thefirst restart counter value indicating the restart of the user equipmentcapability management function may be sent towards the radio accessnetwork.

FIG. 6 illustrates a block diagram of an apparatus 10, in accordancewith some example embodiments.

The apparatus 10 may represent a user equipment, such as the userequipment 150A-150C. The apparatus 10, or portions therein, may beimplemented in other network nodes including base stations/WLAN accesspoints as well as the other network nodes (e.g., devices 152-184).

The apparatus 10 may include at least one antenna 12 in communicationwith a transmitter 14 and a receiver 16. Alternatively transmit andreceive antennas may be separate. The apparatus 10 may also include aprocessor 20 configured to provide signals to and receive signals fromthe transmitter and receiver, respectively, and to control thefunctioning of the apparatus. Processor 20 may be configured to controlthe functioning of the transmitter and receiver by effecting controlsignaling via electrical leads to the transmitter and receiver.Likewise, processor 20 may be configured to control other elements ofapparatus 10 by effecting control signaling via electrical leadsconnecting processor 20 to the other elements, such as a display or amemory. The processor 20 may, for example, be embodied in a variety ofways including circuitry, at least one processing core, one or moremicroprocessors with accompanying digital signal processor(s), one ormore processor(s) without an accompanying digital signal processor, oneor more coprocessors, one or more multi-core processors, one or morecontrollers, processing circuitry, one or more computers, various otherprocessing elements including integrated circuits (for example, anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), and/or the like), or some combination thereof.Accordingly, although illustrated in FIG. 6 as a single processor, insome example embodiments the processor 20 may comprise a plurality ofprocessors or processing cores.

The apparatus 10 may be capable of operating with one or more airinterface standards, communication protocols, modulation types, accesstypes, and/or the like. Signals sent and received by the processor 20may include signaling information in accordance with an air interfacestandard of an applicable cellular system, and/or any number ofdifferent wireline or wireless networking techniques, comprising but notlimited to Wi-Fi, wireless local access network (WLAN) techniques, suchas Institute of Electrical and Electronics Engineers (IEEE) 802.11,802.16, 802.3, ADSL, DOCSIS, and/or the like. In addition, these signalsmay include speech data, user generated data, user requested data,and/or the like.

For example, the apparatus 10 and/or a cellular modem therein may becapable of operating in accordance with various first generation (1G)communication protocols, second generation (2G or 2.5G) communicationprotocols, third-generation (3G) communication protocols,fourth-generation (4G) communication protocols, fifth-generation (5G)communication protocols, Internet Protocol Multimedia Subsystem (IMS)communication protocols (for example, session initiation protocol (SIP)and/or the like. For example, the apparatus 10 may be capable ofoperating in accordance with 2G wireless communication protocols IS-136,Time Division Multiple Access TDMA, Global System for Mobilecommunications, GSM, IS-95, Code Division Multiple Access, CDMA, and/orthe like. In addition, for example, the apparatus 10 may be capable ofoperating in accordance with 2.5G wireless communication protocolsGeneral Packet Radio Service (GPRS), Enhanced Data GSM Environment(EDGE), and/or the like. Further, for example, the apparatus 10 may becapable of operating in accordance with 3G wireless communicationprotocols, such as Universal Mobile Telecommunications System (UMTS),Code Division Multiple Access 2000 (CDMA2000), Wideband Code DivisionMultiple Access (WCDMA), Time Division-Synchronous Code DivisionMultiple Access (TD-SCDMA), and/or the like. The apparatus 10 may beadditionally capable of operating in accordance with 3.9G wirelesscommunication protocols, such as Long Term Evolution (LTE), EvolvedUniversal Terrestrial Radio Access Network (E-UTRAN), and/or the like.Additionally, for example, the apparatus 10 may be capable of operatingin accordance with 4G wireless communication protocols, such as LTEAdvanced, 5G, and/or the like as well as similar wireless communicationprotocols that may be subsequently developed.

It is understood that the processor 20 may include circuitry forimplementing audio/video and logic functions of apparatus 10. Forexample, the processor 20 may comprise a digital signal processordevice, a microprocessor device, an analog-to-digital converter, adigital-to-analog converter, and/or the like. Control and signalprocessing functions of the apparatus 10 may be allocated between thesedevices according to their respective capabilities. The processor 20 mayadditionally comprise an internal voice coder (VC) 20 a, an internaldata modem (DM) 20 b, and/or the like. Further, the processor 20 mayinclude functionality to operate one or more software programs, whichmay be stored in memory. In general, processor 20 and stored softwareinstructions may be configured to cause apparatus 10 to perform actions.For example, processor 20 may be capable of operating a connectivityprogram, such as a web browser. The connectivity program may allow theapparatus 10 to transmit and receive web content, such as location-basedcontent, according to a protocol, such as wireless application protocol,WAP, hypertext transfer protocol, HTTP, and/or the like.

Apparatus 10 may also comprise a user interface including, for example,an earphone or speaker 24, a ringer 22, a microphone 26, a display 28, auser input interface, and/or the like, which may be operationallycoupled to the processor 20. The display 28 may, as noted above, includea touch sensitive display, where a user may touch and/or gesture to makeselections, enter values, and/or the like. The processor 20 may alsoinclude user interface circuitry configured to control at least somefunctions of one or more elements of the user interface, such as thespeaker 24, the ringer 22, the microphone 26, the display 28, and/or thelike. The processor 20 and/or user interface circuitry comprising theprocessor 20 may be configured to control one or more functions of oneor more elements of the user interface through computer programinstructions, for example, software and/or firmware, stored on a memoryaccessible to the processor 20, for example, volatile memory 40,non-volatile memory 42, and/or the like. The apparatus 10 may include abattery for powering various circuits related to the mobile terminal,for example, a circuit to provide mechanical vibration as a detectableoutput. The user input interface may comprise devices allowing theapparatus 20 to receive data, such as a keypad 30 (which can be avirtual keyboard presented on display 28 or an externally coupledkeyboard) and/or other input devices.

As shown in FIG. 6, apparatus 10 may also include one or more mechanismsfor sharing and/or obtaining data. For example, the apparatus 10 mayinclude a short-range radio frequency (RF) transceiver and/orinterrogator 64, so data may be shared with and/or obtained fromelectronic devices in accordance with RF techniques. The apparatus 10may include other short-range transceivers, such as an infrared (IR)transceiver 66, a Bluetooth™ (BT) transceiver 68 operating usingBluetooth™ wireless technology, a wireless universal serial bus (USB)transceiver 70, a Bluetooth™ Low Energy transceiver, a ZigBeetransceiver, an ANT transceiver, a cellular device-to-devicetransceiver, a wireless local area link transceiver, and/or any othershort-range radio technology. Apparatus 10 and, in particular, theshort-range transceiver may be capable of transmitting data to and/orreceiving data from electronic devices within the proximity of theapparatus, such as within 10 meters, for example. The apparatus 10including the Wi-Fi or wireless local area networking modem may also becapable of transmitting and/or receiving data from electronic devicesaccording to various wireless networking techniques, including 6LoWpan,Wi-Fi, Wi-Fi low power, WLAN techniques such as IEEE 802.11 techniques,IEEE 802.15 techniques, IEEE 802.16 techniques, and/or the like.

The apparatus 10 may comprise memory, such as a subscriber identitymodule (SIM) 38, a removable user identity module (R-UIM), an eUICC, anUICC, and/or the like, which may store information elements related to amobile subscriber. In addition to the SIM, the apparatus 10 may includeother removable and/or fixed memory. The apparatus 10 may includevolatile memory 40 and/or non-volatile memory 42. For example, volatilememory 40 may include Random Access Memory (RAM) including dynamicand/or static RAM, on-chip or off-chip cache memory, and/or the like.Non-volatile memory 42, which may be embedded and/or removable, mayinclude, for example, read-only memory, flash memory, magnetic storagedevices, for example, hard disks, floppy disk drives, magnetic tape,optical disc drives and/or media, non-volatile random access memory(NVRAM), and/or the like. Like volatile memory 40, non-volatile memory42 may include a cache area for temporary storage of data. At least partof the volatile and/or non-volatile memory may be embedded in processor20. The memories may store one or more software programs, instructions,pieces of information, data, and/or the like which may be used by theapparatus for performing operations disclosed herein, such as receive afirst user equipment capability identifier associated with a firstrestart counter value indicating a restart of the user equipmentcapability management function; associate the first user equipmentcapability identifier with at least one user equipment capability; andstore the first restart counter value and/or the first user equipmentcapability identifier associated to the at least one user equipmentcapability. Alternatively or additionally, the apparatus may beconfigured to cause the operations disclosed herein with respect to thebase stations/WLAN access points and network nodes including the UEs.

The memories may comprise an identifier, such as an international mobileequipment identification (IMEI) code, capable of uniquely identifyingapparatus 10. The memories may comprise an identifier, such as aninternational mobile equipment identification (IMEI) code, capable ofuniquely identifying apparatus 10. In the example embodiment, theprocessor 20 may be configured using computer code stored at memory 40and/or 42 to the provide operations disclosed herein with respect to theUE, such as receive a first user equipment capability identifierassociated with a first restart counter value indicating a restart ofthe user equipment capability management function; associate the firstuser equipment capability identifier with at least one user equipmentcapability; and store the first restart counter value and/or the firstuser equipment capability identifier associated to the at least one userequipment capability.

Some of the embodiments disclosed herein may be implemented in software,hardware, application logic, or a combination of software, hardware, andapplication logic. The software, application logic, and/or hardware mayreside on memory 40, the control apparatus 20, or electronic components,for example. In some example embodiment, the application logic, softwareor an instruction set is maintained on any one of various conventionalcomputer-readable media. In the context of this document, a“computer-readable medium” may be any non-transitory media that cancontain, store, communicate, propagate or transport the instructions foruse by or in connection with an instruction execution system, apparatus,or device, such as a computer or data processor circuitry, with examplesdepicted at FIG. 6, computer-readable medium may comprise anon-transitory computer-readable storage medium that may be any mediathat can contain or store the instructions for use by or in connectionwith an instruction execution system, apparatus, or device, such as acomputer.

Without in any way limiting the scope, interpretation, or application ofthe claims appearing below, a technical effect of one or more of theexample embodiments disclosed herein may be improved signaling.

The subject matter described herein may be embodied in systems,apparatus, methods, and/or articles depending on the desiredconfiguration. For example, the base stations and user equipment (or oneor more components therein) and/or the processes described herein can beimplemented using one or more of the following: a processor executingprogram code, an application-specific integrated circuit (ASIC), adigital signal processor (DSP), an embedded processor, a fieldprogrammable gate array (FPGA), and/or combinations thereof. Thesevarious implementations may include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device. Thesecomputer programs (also known as programs, software, softwareapplications, applications, components, program code, or code) includemachine instructions for a programmable processor, and may beimplemented in a high-level procedural and/or object-orientedprogramming language, and/or in assembly/machine language. As usedherein, the term “computer-readable medium” refers to any computerprogram product, machine-readable medium, computer-readable storagemedium, apparatus and/or device (for example, magnetic discs, opticaldisks, memory, Programmable Logic Devices (PLDs)) used to providemachine instructions and/or data to a programmable processor, includinga machine-readable medium that receives machine instructions. Similarly,systems are also described herein that may include a processor and amemory coupled to the processor. The memory may include one or moreprograms that cause the processor to perform one or more of theoperations described herein.

Although a few variations have been described in detail above, othermodifications or additions are possible. In particular, further featuresand/or variations may be provided in addition to those set forth herein.Moreover, the implementations described above may be directed to variouscombinations and subcombinations of the disclosed features and/orcombinations and subcombinations of several further features disclosedabove. Other embodiments may be within the scope of the followingclaims.

If desired, the different functions discussed herein may be performed ina different order and/or concurrently with each other. Furthermore, ifdesired, one or more of the above-described functions may be optional ormay be combined. Although various aspects of some of the embodiments areset out in the independent claims, other aspects of some of theembodiments comprise other combinations of features from the describedembodiments and/or the dependent claims with the features of theindependent claims, and not solely the combinations explicitly set outin the claims. It is also noted herein that while the above describesexample embodiments, these descriptions should not be viewed in alimiting sense. Rather, there are several variations and modificationsthat may be made without departing from the scope of some of theembodiments as defined in the appended claims. Other embodiments may bewithin the scope of the following claims. The term “based on” includes“based on at least.” The use of the phase “such as” means “such as forexample” unless otherwise indicated.

What is claimed:
 1. An apparatus comprising: at least one processor; andat least one memory including computer program code, the at least onememory and the computer program code configured to, with the at leastone processor, cause the apparatus to at least: receive, from a userequipment capability management function, a message including a firstrestart counter value indicating a restart of the user equipmentcapability management function; inhibit, in response to receiving thefirst restart counter value, one or more old user equipment capabilityidentifiers associated with a second restart counter value, the secondrestart counter value being associated to a pre-restart state of theuser equipment capability management function; and send the firstrestart counter value indicating the restart of the user equipmentcapability management function.
 2. The apparatus of claim 1, wherein theapparatus is further caused to at least store the first restart countervalue.
 3. The apparatus of claim 1, wherein the apparatus is furthercaused, when the apparatus receives a registration request including auser equipment capability identifier associated with the second restartcounter value and/or when inspecting for one or more user equipmentcapability identifiers being stored for registered user equipment, to atleast compare the second restart counter value to the first restartcounter value to determine whether the second restart counter valuematches the first restart counter value.
 4. The apparatus of claim 1,wherein the apparatus is further caused to at least send, to the radioaccess network, a message to trigger retrieval of a user equipmentcapability information for a user equipment.
 5. The apparatus of claim4, wherein the message is sent, when the apparatus does not include inits cache a user equipment capability identifier associated to thesecond restart counter value.
 6. The apparatus of claim 1, wherein theapparatus is further caused to at least assign, to a user equipment, anew user equipment capability identifier associated to the userequipment capability information including at least one radiocapability, wherein the new user equipment capability identifier isassociated to the first restart counter value.
 7. The apparatus of claim6, wherein the assigned, new user equipment capability identifier issent to the user equipment in a registration accept message, aconfiguration update message, a globally unique temporary identifierreallocation command message, and/or a non-access-stratum signalingmessage.
 8. The apparatus of claim 1, wherein the apparatus is furthercaused to at least send a new user equipment capability identifierand/or the first restart counter value to a radio access network toenable the radio access network to inhibit the use of the one or moreold user equipment capability identifiers associated to the secondrestart counter value and/or caused to at least store the user equipmentcapability identifier associated with the first restart counter valueand/or the first restart counter.
 9. The apparatus of claim 1, whereinthe apparatus is further caused to at least send, toward one or moreuser equipment, context information including the old user equipmentradio capability identifier associated to the second restart countervalue.
 10. The apparatus of claim 1, wherein the first restart countervalue indicating the restart of the user equipment capability managementfunction is sent towards the radio access network.
 11. The apparatus ofclaim 1, wherein the apparatus is comprised in or comprises a corenetwork node, an access and mobility management function, and/or amobility management entity.
 12. An apparatus comprising: at least oneprocessor; and at least one memory including computer program code, theat least one memory and the computer program code configured to, withthe at least one processor, cause the apparatus to at least: receive afirst user equipment capability identifier associated with a firstrestart counter value indicating a restart of the user equipmentcapability management function; associate the first user equipmentcapability identifier with at least one user equipment capability; andstore the first restart counter value and/or the first user equipmentcapability identifier associated to the at least one user equipmentcapability.
 13. The apparatus of claim 12, wherein the apparatus isfurther caused to at least send, to a core network via a radio accessnetwork, a registration request including the first user equipmentcapability identifier associated to the first restart counter value. 14.The apparatus of claim 12, wherein the first restart counter valueindicates a more recent restart of the user equipment capabilitymanagement function when compared to a second restart counter valueassociated to a second user equipment capability identifier for theapparatus.
 15. The apparatus of claim 14, wherein the apparatus isfurther caused to at least inhibit, in response to the received firstuser equipment capability identifier, use of the second user equipmentcapability identifier.
 16. The apparatus of claim 15, wherein theinhibition of the second user equipment capability identifier comprisesdeleting the second user equipment capability identifier.
 17. Theapparatus of claim 12, wherein the apparatus is further caused to atleast cache one or more user equipment capability identifiers associatedto the second restart counter value after receipt of the first userequipment capability identifier associated to the first restart countervalue, the cache including the corresponding user equipment capabilityinformation.
 18. The apparatus of claim 12, wherein the first userequipment capability identifier associated to the first restart countervalue is received via a registration accept message, a configurationupdate message, a globally unique temporary identifier reallocationcommand message, and/or a non-access-stratum signaling message.
 19. Theapparatus of claim 12, wherein the first user equipment capabilityidentifier is sent to a radio access network.
 20. A method comprising:receiving, from a user equipment capability management function, amessage including a first restart counter value indicating a restart ofthe user equipment capability management function; inhibiting, inresponse to receiving the first restart counter value, one or more olduser equipment capability identifiers associated with a second restartcounter value, the second restart counter value being associated to apre-restart state of the user equipment capability management function;and sending the first restart counter value indicating the restart ofthe user equipment capability management function.
 21. The method ofclaim 20, further comprising: when a registration request is receivedincluding a user equipment capability identifier associated with thesecond restart counter value and/or when inspecting for one or more userequipment capability identifiers being stored for registered userequipment, comparing the second restart counter value to the firstrestart counter value to determine whether the second restart countervalue matches the first restart counter value.
 22. The method of claim20, further comprising: sending, to the radio access network, a messageto trigger retrieval of a user equipment capability information for auser equipment.
 23. The method of claim 22, wherein the message is sent,when a cache does not include a user equipment capability identifierassociated to the second restart counter value.
 24. The method of claim20, further comprising: assigning, to a user equipment, a new userequipment capability identifier associated to the user equipmentcapability information including at least one radio capability, whereinthe new user equipment capability identifier is associated to the firstrestart counter value.
 25. The method of claim 24, wherein the assigned,new user equipment capability identifier is sent to the user equipmentin a registration accept message, a configuration update message, aglobally unique temporary identifier reallocation command message,and/or a non-access-stratum signaling message.
 26. The method of claim20, further comprising: sending a new user equipment capabilityidentifier and/or the first restart counter value to a radio accessnetwork to enable the radio access network to inhibit the use of the oneor more old user equipment capability identifiers associated to thesecond restart counter value and/or caused to at least store the userequipment capability identifier associated with the first restartcounter value and/or the first restart counter.
 27. The method of claim20, further comprising: sending, toward one or more user equipment,context information including the old user equipment radio capabilityidentifier associated to the second restart counter value.
 28. A methodcomprising: receiving a first user equipment capability identifierassociated with a first restart counter value indicating a restart ofthe user equipment capability management function; associating the firstuser equipment capability identifier with at least one user equipmentcapability; and storing the first restart counter value and/or the firstuser equipment capability identifier associated to the at least one userequipment capability.
 29. The method of claim 28, wherein the apparatusis further caused to at least send, to a core network via a radio accessnetwork, a registration request including the first user equipmentcapability identifier associated to the first restart counter value. 30.The method of claim 28, wherein the first restart counter valueindicates a more recent restart of the user equipment capabilitymanagement function when compared to a second restart counter valueassociated to a second user equipment capability identifier for theapparatus.
 31. The method of claims 30, further comprising: inhibiting,in response to the received first user equipment capability identifier,use of the second user equipment capability identifier.
 32. The methodof claim 28, further comprising: caching one or more user equipmentcapability identifiers associated to the second restart counter valueafter receipt of the first user equipment capability identifierassociated to the first restart counter value, the cache including thecorresponding user equipment capability information.
 33. The method ofclaim 28, wherein the first user equipment capability identifierassociated to the first restart counter value is received via aregistration accept message, a configuration update message, a globallyunique temporary identifier reallocation command message, and/or anon-access-stratum signaling message.